Posts Tagged ‘satellite’

Land surface temperatures in USA in 2012 March, red for warm anomalies and blue for cool. Image: Earth Observatory, NASA

NASA’s Earth Observatory has an image-story on how a huge, lingering ridge of high pressure over the eastern half of the United States brought summer-like temperatures to North America in March 2012. The warm weather broke records across the central and eastern United States and much of Canada.

The unseasonable warmth broke temperature records in more than 1,054 locations between March 13–19, as well daily lows in 627 locations. Cities as geographically diverse as Chicago, Des Moines, Traverse City (Michigan), Myrtle Beach, Madison (Wisconsin), Atlantic City, New York City, and Duluth, (Minnesota) all broke records for high temperatures in recent days.

The intensity and scope of the heat wave is clearly visible in this map of land surface temperature anomalies. Based on data from the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument on the Terra satellite, the map depicts temperatures compared to the average of the same eight day period of March from 2000-2011. Areas with warmer than average temperatures are shown in red; near-normal temperatures are white; and areas that were cooler than the 2000-2011 base period are blue.

UARS fell back 20 years and nine days after its launch on a 14-year mission that produced some of the first long-term records of chemicals in the atmosphere. NASA has said the precise re-entry time and location of debris impacts have not been determined. During the re-entry period, the satellite passed from the east coast of Africa over the Indian Ocean, then the Pacific Ocean, then across northern Canada, then across the northern Atlantic Ocean, to a point over West Africa. The vast majority of the orbital transit was over water, with some flight over northern Canada and West Africa.

“Most of the time we do rely heavily on people on the ground,” Nick Johnson, chief orbital debris scientist at NASA’s Johnson Space Center in Houston, told reporters in a news briefing Saturday (Sept. 24). “UARS, whether it came in during the local day or local night, would have clearly been visible.” Johnson said there were some people along the western coast of North America that were hoping to capture views of the dying satellite. Since the agency did not receive any plausible reports, this would further suggest that UARS did, in fact, splash down in the ocean without ever reaching North America.

Reuters has reported that at 35 feet long and 15 feet in diameter, UARS was among the largest spacecraft to plummet uncontrollably through the atmosphere, although it is a slim cousin to NASA’s 75-tonne (68,000 kilogram) Skylab station, which crashed to Earth in 1979. Russia’s last space station, the 135-tonne (122,000 kilogram) Mir, crashed into the Pacific Ocean in 2001, but it was a guided descent. NASA now plans for the controlled re-entry of large spacecraft, but it did not when UARS was designed.

Six years after the end of its productive scientific life, UARS broke into pieces during re-entry, and most of it up burned in the atmosphere. Data indicates the satellite likely broke apart and landed in the Pacific Ocean far off the U.S. coast. Twenty-six satellite components, weighing a total of about 1,200 pounds, could have survived the fiery re-entry and reach the surface of Earth. However, NASA is not aware of any reports of injury or property damage. The Operations Center for JFCC-Space, the Joint Functional Component Command at Vandenberg Air Force Base, Calif., which works around the clock detecting, identifying and tracking all man-made objects in Earth orbit, tracked the movements of UARS through the satellite’s final orbits and provided confirmation of re-entry.

Update 20110924-pm(Asia): UARS has landed. NASA’s decommissioned Upper Atmosphere Research Satellite fell back to Earth between 11:23 p.m. EDT Friday, Sept. 23 and 1:09 a.m. EDT Sept. 24. The Joint Space Operations Center at Vandenberg Air Force Base in California said the satellite penetrated the atmosphere over the Pacific Ocean. The precise re-entry time and location are not yet known with certainty (from NASA Update No. 15).

Update 20110924: New updates from NASA on the re-entry path of UARS and possible times of re-entry. Background on predictive models of space debris. Description on kinds of debris that may be expected.

From mapping out the track of a hurricane to monitoring the melting of ice caps, satellites are heavily relied on in science. The Upper Atmosphere Research Satellite (UARS), which has been languishing in orbit for six years, is now on the verge of falling back to Earth, NASA announced in September 2011. In this photo, the UARS hangs in the grasp of the Remote Manipulator System during deployment from Space Shuttle Discovery in September 1991. Photo: NASA Marshall Space Flight Center

NASA Update No. 13 – the orbit of UARS was 85 miles by 90 miles (135 km by 140 km). Re-entry was expected between 11:45 p.m. Friday, Sept. 23, and 12:45 a.m., Sept. 24, Eastern Daylight Time (3:45 a.m. to 4:45 a.m. GMT). During that time period, the satellite was passing over Canada and Africa, as well as vast areas of the Pacific, Atlantic and Indian oceans. The risk to public safety was very remote. NASA is working to confirm the re-entry location and time and will provide an update shortly. [NASA Update No. 12 was not substantially different from No. 13]

NASA Update No. 11 – the orbit of UARS was 90 miles by 95 miles (145 km by 150 km). Re-entry is expected between 11 p.m. Friday, Sept. 23, and 3 a.m., Sept. 24, Eastern Daylight Time (3 a.m. to 7 a.m. GMT). During that time period, the satellite will be passing over Canada, Africa and Australia, as well as vast areas of the Pacific, Atlantic and Indian oceans. The risk to public safety is very remote.

To foresee the paths of space junk so that collisions can be avoided, NASA developed one of the world’s most sophisticated predictive models, as Technology Review has explained. Called Legend (for “low-Earth to geosynchronous environment debris”), the three-dimensional model simulates the routes of all trackable space objects and even factors in new debris from future crashes. To take uncertainty and randomness into account, hundreds of scenarios are generated using the Monte Carlo method, a set of algorithms that can calculate risk factors in a complex environment. With Legend, NASA scientists use the average of multiple simulations to estimate the number, size, and type of objects that will collide—and approximately how often. Unlike models used by the U.S. Strategic Command Joint Space Operations Center, which detects and tracks large objects and screens active satellites daily for possible collisions within 72 hours, Legend includes smaller fragments and looks far into the future.

In place since 2004, the NASA model is constantly fed with data gathered from the results of ground tests and spacecraft that have broken up in orbit; from telescopes and radars viewing the sky; and from analysis of crater-marked spacecraft surfaces that have returned to Earth. That means new simulations must be run continually. Legend enables scientists to calculate the consequences of a particular breakup or collision and helps them alert managers at the space station that a piece of debris could be in its path. The model also advises soon-to-launch satellites of areas to avoid and will guide scientists as they attempt to develop and launch debris removal technology for the first time.

From NASA Orbital Debris Program Office: “After spacecraft (or parent body) breakup, individual components, or fragments, will continue to lose altitude and receive aeroheating until they either demise or survive to impact the Earth. Spacecraft components that are made of low melting-point materials (e.g., aluminum) will generally demise at higher altitudes than objects that are made of materials with higher melting points (e.g., titanium, stainless steel, beryllium, carbon-carbon). If an object is contained inside of a housing, the housing must demise before the internal object receives significant heating. Many objects have a very high melt temperature such that they do not demise, but some can be so light (e.g., tungsten shims) that they impact with a very low velocity. As a result, the kinetic energy at impact is sometimes under 15 J, a threshold below which the probability of human casualty is very low.”

This conceptual image shows the Upper Atmosphere Research Satellite, launched on Sept. 15, 1991, by the space shuttle Discovery. Originally designed for a three-year mission, UARS measured chemical compounds found in the ozone layer, wind and temperature in the stratosphere, as well as the energy input from the sun. Together, these measurements helped define the role of Earth's upper atmosphere in climate and climate variability. The 35-foot-long, 15-foot-diameter UARS was decommissioned on Dec. 14, 2005. Credit: NASA

Earlier: First, get the data from the owners, NASA. Second, read the onlnie news and watch TV, but keep track of what the orbital experts are saying – Space Track, Space Data Source, NASA’s Orbital Debris Program Office, the Joint Space Operations Center of U.S. Strategic Command. Third, keep handy some basics about the falling satellite (a few pointers follow).

Spread of surviving debris

NASA’s latest update: As of 10:30 a.m. EDT on Sept. 23, 2011, the orbit of UARS was 100 miles by 105 miles (160 km by 170 km). Re-entry is expected late Friday, Sept. 23, or early Saturday, Sept. 24, Eastern Daylight Time. Solar activity is no longer the major factor in the satellite’s rate of descent.

The satellite’s orientation or configuration apparently has changed, and that is now slowing its descent. There is a low probability any debris that survives re-entry will land in the United States, but the possibility cannot be discounted because of this changing rate of descent. It is still too early to predict the time and location of re-entry with any certainty, but predictions will become more refined in the next 12 to 18 hours.

Casualty risk assessment

NASA has been posting updates daily until about 24 hours before re-entry, and then at about 12 hours, six hours and two hours before re-entry. The updates will come from the Joint Space Operations Center of U.S. Strategic Command at Vandenberg Air Force Base, Calif., which works around the clock detecting, identifying and tracking all man-made objects in Earth orbit, including space junk.

As of Sept. 8, 2011, the orbit of UARS was 152 miles by 171 miles (245 km by 275 km) with an inclination of 57 degrees. Because the satellite’s orbit is inclined 57 degrees to the equator, any surviving components of UARS will land within a zone between 57 degrees north latitude and 57 degrees south latitude. It is impossible to pinpoint just where in that zone the debris will land, but NASA estimates the debris footprint will be about 500 miles long.

Advice: If you find something you think may be a piece of UARS, do not touch it. Contact a local law enforcement official for assistance.

UARS starboard view

UARS Reentry Predictions
The official source of reentry predictions for uncontrolled space objects is USSTRATCOM’s Joint Space Operations Center (JSpOC).
Normal procedure is for TIP (Tracking and Impact Prediction) messages to be prepared and released to the public (via the Space-Track.org website) at the following intervals: – T-4 days, T-3 days, T-2 days, T-1 day, T-12 hours, T-6 hours, and T-2 hours.
TIP messages provide the best estimates of reentry time and location but have large uncertainties. Even at T – 2 hours, the uncertainty of reentry time is on average +/- 25

UARS port view

minutes for nearly circular orbits. This equates to +/- 12,000 km on the Earth.
A final, post-reentry assessment message is normally issued within a few hours of reentry. This reentry prediction comes from the ‘Re-entry and Risk Assessment for the NASA Upper Atmosphere Research Satellite (UARS)’ document [get it here, pdf], NASA Orbital Debris Program Office, Lyndon B. Johnson Space Center.

08 February 2017: A month short of six years after the 11 March Fukushima disaster began unfolding, the situation at the nuclear power plant has entered a new phase of danger, one which modern industrial civilisation has no experience with and very little knowledge about.

Street lights shine in the abandoned town of Iitate, outside the 20 kilometre exclusion zone around the Fukushima No. 1 Nuclear Power Plant, in northeast Japan. Residents were forced to evacuate the town after radiation levels from the leaking plant exceeded those inside the exclusion zone. Nov. 20, 2011. Photo: Mainichi Daily News / AP Photo / Greg Baker

More than nine months have passed since the 11 March earthquake and tsunami that devastated northeastern Japan and triggered a still-unresolved disaster at the Fukushima No. 1 Nuclear Power Plant. This set of news reports, news features and editorial in the Mainichi Daily News reveals the chronic deception and criminal corporate irresponsibility that continue to hinder all meaningful effort to mitigate the meltdown, and to obstruct at all costs the truth.

In the meantime, rebuilding the lives of residents near the crippled plants has been an urgent critical challenge. On the occasion of its latest political declaration, the government needs to renew its resolve to settle the crisis and achieve regional recovery. The disaster-hit reactors are certainly now in a more stable condition. However, the phrase “cold shutdown” usually refers to suspension of a sound reactor. The fact that the government is attempting to apply this term in a severe accident in which three reactors have suffered core meltdowns should be called into question. The government should rather explain in detail the possibility of any additional explosions and whether a recriticality accident has been ruled out.

Simulations suggest that nuclear fuel has melted inside the reactor containment vessels, eroding their concrete floors. Although Tokyo Electric Power Co. (TEPCO), the operator of the stricken nuclear plant, has indicated that melted fuel has also been cooled down by water, this is nothing but speculation. We urge the utility and the government to find a way to ascertain the precise condition of the fuel.

Mainichi Daily News has reported that conditions at the Fukushima No. 1 nuclear plant are far worse than its operator or the government has admitted, according to freelance journalist Tomohiko Suzuki, who spent more than a month working undercover at the power station. “Absolutely no progress is being made” towards the final resolution of the crisis, Suzuki told reporters at a Foreign Correspondents’ Club of Japan news conference on Dec. 15. Suzuki, 55, worked for a Toshiba Corp. subsidiary as a general laborer there from July 13 to Aug. 22, documenting sloppy repair work, companies including plant operator Tokyo Electric Power Co. (TEPCO) playing fast and loose with their workers’ radiation doses, and a marked concern for appearances over the safety of employees or the public.

An earthquake-damaged grave is seen at a cemetery in the abandoned town of Katsurao, outside the 20 kilometre exclusion zone around the Fukushima No. 1 Nuclear Power Plant, in northeast Japan. The town was abandoned when radiation levels became unsafe for long term exposure. Nov. 20, 2011. Photo: Mainichi Daily News / AP Photo / Greg Baker

For example, the no-entry zones around the plant – the 20-kilometer radius exclusion zone and the extension covering most of the village of Iitate and other municipalities – have more to do with convenience that actual safety, Suzuki says. The situation at the plant itself is no better, where he says much of the work is simply “for show,” fraught with corporate jealousies and secretiveness and “completely different” from the “all-Japan” cooperative effort being presented by the government.

“Reactor makers Toshiba and Hitachi (brought in to help resolve the crisis) each have their own technology, and they don’t talk to each other. Toshiba doesn’t tell Hitachi what it’s doing, and Hitachi doesn’t tell Toshiba what it’s doing.” Meanwhile, despite there being no concrete data on the state of the reactor cores, claims by the government and TEPCO that the disaster is under control and that the reactors are on-schedule for a cold shutdown by the year’s end have promoted a breakneck work schedule, leading to shoddy repairs and habitual disregard for worker safety, he said. “Working at Fukushima is equivalent to being given an order to die,” Suzuki quoted one nuclear-related company source as saying.

At a Tokyo market, a smartphone shows radiation test results by the grower of a package of Maitake mushrooms, showing them as free of radioactive contamination. Many consumers worry about the safety of food from Fukushima and surrounding prefectures, although produce and fish found to be above government-set limits for contamination are barred from the market. Mushrooms, for example, harvested in and around Fukushima are frequently found to be contaminated and barred from the market. Sept. 12, 2011. Photo: Mainichi Daily News / AP Photo / Shizuo Kambayashi

Following the nuclear disaster at the Fukushima No. 1 power plant, triggered by the March 11 earthquake and tsunami, Oshima’s situation drastically changed. He was selected as a member of two expert governmental committees to serve as a critical analyst of Japan’s current nuclear power stance. The group will openly release all internal debates and documents, Oshima says. He is now more optimistic than ever that the time to destroy the “cheap and safe” nuclear power myth will eventually come.

A sober and critical editorial in the Mainichi Daily News has said that Britain has already abandoned developing fast-breeder nuclear reactors, and is set to give up nuclear fuel reprocessing as well. Moreover, its planned construction of a facility to dispose of radioactive waste including plutonium is likely to materialize even though it is still at a planning phase.

In contrast, there are no prospects that Japan can build a disposal facility. However, for Japan to call for operations at the Monju prototype fast-breeder nuclear reactor in Fukui Prefecture and the nuclear fuel reprocessing plant in the Aomori Prefecture village of Rokkasho to be carried out as planned, would be like putting the cart before the horse as it appears the country is incapable of building a disposal facility.

Plutonium is directly related to security issues. The U.K. possesses nuclear weapons but Japan does not. One may wonder whether Japan’s independence will be threatened if it abandons nuclear fuel recycling and loses its ability to produce plutonium. Even though it is an important point of contention the issue should not be used as a reason to underestimate the harm of plutonium.

Economy, Trade and Industry Minister Yukio Edano who is in charge of energy policy, Goshi Hosono, state minister for handling the nuclear crisis, and Yoshito Sengoku, second-in-command in the ruling Democratic Party of Japan’s Policy Research Committee, have been hearing the views of experts on the issue. It is not enough for the government to talk only about the dream of “prosperity” built on dependence on nuclear power. Japan’s ability to overcome the mess that follows such prosperity is now being tested.